Process of refining hydrocarbon oil



success or an l Paul J. Carlisle, a l g mesne assients... w E, mom andny, a aeration of a attain I N. Yep L- r du Pont de New No Drawing.Application May 12, 1931.,

Serial No. 53$.t2d 1 This invention relates-to the refining ofhydrocarbons and more particularly to a process for refining hydrocarbonoils by adsorbent material and alkali metal.

Hydrocarbon oils, for instance lubricating oils, are frequently refinedby treating with adsorbent materials, such as iullers earth. A largenumber 5 of methods of using fuller's earth and like rbents have beenproposed, but the two most commen methods are: (a) the contact process,wherein the oil is agitated for a time with the adsorbent at a definitetemperature and then illtered, and (b) the percolation process, whereinthe oil is filtered through a thick bed of adsorbcut. These treatmentsare often preceded by treatmentwith sulfuric acid or other chemical.

adsorbents as heretofore used have been somewhat unsatisfactory asrefining agents because of their relative inactivity toward the oil.This often makes it necessary to treat the oil many times before thedesired quality is obtained. Large amounts of adsorbent are required perunit of treated oil recovered. Moreover large amounts of oil becomeentrained in the adsorbent necessitating expensive solvent extractionsand subsequent separations for recovery. Even then the adsorbent itselfis useless for further refining until revlvifled or reactivated by a.costly burning out process in which quantities of both oil and solventare lost.

' It has been proposed to subject hydrocarbon oils in the vapor phase tosuccessive treatments with metal and adsorbent. Vapor phase treatmentsare often unsuited to the treatment of the higher boiling hydrocarbonssuch as lubricating oils, because of the high temperatures requiredwhich cause cracking. Furthermore, this method of refining by metaltreatment is usually uneconomical when-reactive metals like the alkalito metals are used because insoluble treatment'byproducts areformedwhich foul the metal before it is used up. It then becomesnecessary in or- .der to avoid waste of metal, to recover the unreactedmetal from the by-products, which is a relatlvely diflicult and costlyoperation. An object of this invention is to provide a relativelyeconomical method of producing highly refined hydrocarbon oils. Afurther object is to enhance the utility or small amounts of alkalimetal in treating hydrocarbons and simultaneously to increase theproductivity and simplify the use of adsorbent refining agents.

[These objects may be accomplished according, to. my invention byacombination of treatments with alkali metal and anvadsorbent material,for

(fit. Edd-23) instance fullers earth, wherein the metal is substantiallyentirely consumed. Such combln instance by such treatment a practicallyneutral 15' oil may be rendered highly alkaline and of low resistance tooxidation. It therefore has been found necessary, as disclosed in theabove mentioned copending application, to use an excess of alkali metalin order to obtain an oil of good 20 quality. I have now discovered thesurprising fact that fullers earth, although a muchless reactivetreating agent than alkali metal, may be used in place of the aforesaidexcess. It'appears to be immaterial whether the oil is treated simul- 25taneously or consecutively with alkali metal and fullers earth, providedthat a substantial excess of the alkali metal is not used.

One method of carrying out my invention will now be described: alkalimetal is added to the 30 oil in a suitable vessel, for instance, anirontank, and the mixture is agitated at a temperature above the meltingpoint of the metal and below cracking temperatures until substantiallyall the metal has reacted. This point may be deter- 35 mined by applyinga chemical test for the metal to small samples of the oil, withdrawn atintervals of time. The oil is then filtered to remove insolubletreatment by-products, and the filtered I oil is subsequently treatedwith an adsorbent ma- 4;) terial by any feasible method. I prefer to,treat. the oil with a finely divided, for example -200 mesh, fuller'searth by either the contact or percolation method.

The proportional weight of alkali metal used 45 may be varied accordingto the quality of product desired, provided that the amount of metaladded is such that it will be substantially entirely consumed during thetreatment. The W 2'1 um amount of metal that react when contacted 50with the oil under given conditions for a given "period of tlmecan bedetermined by preliminary experiments on small batches.

Another method of carrying out my invention comprises adding a mixtureor alkali metal and as adsorbent material such as fuller's earth to theoil, heating and agitating until the metal is sub stantially entirelyconsumed and subsequently filtering ed the insoluble materials. Byapplying several treatments successively, various grades of oil may beobtained, the degree of refinement depending on the number of treatmentsand the amounts of alkali metal and adsorbent used in 1 each.

My invention may be used to obtain the same Example 1 Forty grams ofsodium were added to 4 liters of a Pennsylvania oil and the mixture wasstrong 1v agitated at 225 C..until a test showed that no appreciableamount of the metal remained. The mixture was then filtered and theinsoluble portion was extracted with solvent naphtha to re move adheringoil. The extract was distilled to separate solvent from the oil and thelatter was added to the filtrate.

A 400 cc. portion of the filtered oil was percolated once through a bedof 650'grams of fullers earth which had been previously activated byheating to 400 C., comprising a 5 inch layer of 100-200 mesh earthcovered witha l-inch layer of 30-60 mesh earth.

Another quantity of the same oil was percolated once through fullersearth under the same conditions and using the same ratio of oil tofuller's earth, but without the previous alkali metal treatment.

The results are given in the following table. The indicatedcharacteristics of the-oils were determined by standard methodsestablished by the American Society for Testing Materials.

Characteristics of the oils 0" permilfmd untroeizlated Neutralization No0.00 0.00 0.00 Bligh Oxidation No. 0. 6.2 Steam Emulsion No- 0. 22.0sec. Visc. 100 134.0 sec. Visc. at 210 F 43.0 sec Flash point, F. 390Fire point, F 456 Color, N. P. A No. l

Yield (bbls. of oil obtained for ton oi iuller's earth used) 3.6 3.6

Example 2 A Pennsylvania oil was treated with sodium and filtered asdescribed in Example 1 but not percolated and then was subjected to foursuccessive treatments with fuller's earth, by the contact method. Eachcontact treatment comprised agitating the oil at C. with 250 grams oi.earth per liter of oil for 10 minutes, and filtering.

Another portion of this oil, not treated with sodium, was subjected toseven successive contact treatments with fuiler's earth. each treatmentbeing identical with those given the sodium treated oil.

The results are given in the following table:

Pennsylvania oil was treated by strongly agitating for 30 minutes at 225C. with a mixture of 10 grams of sodium and 250 grams of fuller's earthper liter of oil. The mixture was then filtered and the same treatmentwas applied to the filtrate. In both treating operations the sodium wassubstantially entirely consumed.

To other portions of the same oil were subjected to successivetreatments with iuller's earth alone, using 250 grams of earth per literof oil for each treatment and the same conditions as above. One of theseportions was given two fullers earth treatments and the other, seven.

The following table indicates the degree of refining obtained in eachcase: i

While I prefer in my process to contact alkali metal with the oil at atemperature between the melting point of the metal and the crackingpoint of the oil, for instance at -250 C., other temperatures may beused, although, according to my experience, not so advantageously.Likewise, the alkali metal treatment may be carried out at eitherincreased pressures or under vacuum, as

well as at atmospheric pressure.

The treatment with fullers earth or other adsorbent may be carried. outby any known method, and any number of successive treatments may beused, withoutdeparting from the, spirit and scope of my invention.Besides fulier's earth, other adsorbents, such as silica gel or aluminagel, may be used.

Although I have described my invention as a process for refininghydrocarbon oils by means of alkali metal, it is not limited 'thereto..The process may be carried out by using any metallic refining agentwhich chemically reacts during the refining process so that it therebymay be substantially entirely consumed. Such metals in-' ciude notonlyalkali metals but also their alloys and other metals and alloyswhich react with the constituents and/or impurities of the oil to berefined. The metallic'refining agent may be used in either the fusedstate or as a finely divided solid metal.

Various modifications and adaptations of my invention may be usedwithout departing from the spirit and scope thereof. For instance, thestep comprising treating the oil with metal may be divided into a numberof successive treatments. Also, the treatment with metal may be followedby any desired number of treatments with adsorbent or mixtures of metaland adsorbent, or by various combinations of successive treatments withadsorbent and adsorbent-alkali metal mixtures. A further possiblemodification is to follow a' treatment with a mixture of metal andadsorbent by treatment with adsorbent alone. A still furthermodification is to follow the metal treatment with the adsorbenttreatment, omitting the intermediate step of removing insolubletreatment by-products.

Although I have described my invention by reference to a batch process,it may also be practiced as a continuous process. For instance thecombination of a continuous liquid phase treatment with alkali metal,with a continuous process for treatment with adsorbent material comeswithin the scope of the present invention.

Other variations of my invention will be apparent to persons skilled inoil refining.

My process may be used to refine any liquid or solid hydrocarbons andthe like, or solutions of gaseous hydrocarbons, no matter what theirsource or previous treatment. Thus it is equally applicable to oilswhich have been treated with sulfuric acid or other chemical and thosewhich have had no pre-treatment of any kind. Likewise, it is equallyapplicable to the treatment of low-boiling hydrocarbons, such asgasoline and to the heavy hydrocarbons, such as lubricating oils. Italso may be applied 'to the treatment of gaseous hydrocarbons dissolvedin solvents which are not incompatible with the metallic treating agentused. a

My process is especially useful in treating certain hydrocarbonproducts, for instance those obtained from Pennsylvania crude oils,which often cannot be advantageously treated with suliuric acid.

One advantage oi my invention is that by its use oils of a given qualitymay be produced by the use of much less fullers earth than the processesnow commonly practiced. Another advantage is that by my process oils ofhigh quality, for instance colorless medicinal oils, may be producedwith a comparatively mild fullers earth treatment, in contrast to thedrastic acid and fullers' earth treatments heretofore necessary.

A further advantage of my invention is that it enables the alkali metaltreatment of heavy liquid hydrocarbons to be carried out without usingan excess of the metal, and thus avoids the troublesome and costly stepof recovering unreacted metal. Heretofore, in order to obtainsatisfactory refinement, it has been necessary to treat hydrocarbon oilswith from 25% to around 200% excess of alkali metal. The recovery of theexcess unreacted metal from treatment by-procl-' ucts is difficult andcostly and considerable metal is often lost in attempting such recovery.My

invention eliminates the troublesome recovery step and avoids any wasteof metal.

To obtain the various degrees of refinement that may be desired, theamount of. metal used, factors such as; temperature, time and degree ofagitation, andthe extent of treatment with adsorbent may be variedaccording to the quality of oil desired. Obviously, the extent oftreatment and modification of'my method necessary to produce oil 0! acertain grade will depend largei? on a viscosity of more than 50seconds, Saybolt Universal at 100 F. The term hydrocarbons is understoodto mean substances composed mainly of carbon-hydrogen compounds, butwhich may contain appreciable amounts of other substances as impurities.For the sake of brevity, the term "reactive metal in the claims, is usedto designate any metal or alloy capable of chemically reacting with theconstituents and/or impurities of the hydrocarbon being treated.

I claim:-

I. A process for refinlng'hydrocarbon oils comprising contactinghydrocarbon oil in the liquid phase with a quantity of alkali metal lessthan that required to produce a neutral oil at a temperature between themelting point of the metal and the temperature at which materialdecomposition of the oil occurs, under such conditions that the alkalimetal is substantially entirely consumed, filtering the insolublereaction products from said oil and thereafter treating said oil withadsorbent material.

2. A process for refining hydrocarbon oils comprising contactinghydrocarbon oil in the liquid phase with a quantity of sodium less thanthat required to produce a neutral oil at l00-250 C., under suchconditions that the sodium is substantially entirely consumed, filteringthe insoluble reaction products from said oil and thereafter treatingsaid oil with fuller's earth.

3. A process for refining hydrocarbon oils comprising adding sodium tohydrocarbon oil in the liquid phase in an amount less than that whichwill produce a neutral oil, heating and agitating the mixture at 100-250C. until the sodium is substantially entirely reacted, removinginsoluble treatment by-products from said oil and thereafter treatingsaid oil with fuller's earth.

4. A process according to claim 3, in which the step comprising heatingand agitating with sodium and removing insoluble by-products'is dividedinto a plurality of successive operations.

5. A process for refining a liquid hydrocarbon comprising agitatingliquid hydrocarbon with molten sodium, the proportion of sodium tohydrocarbon being less than that required to produce a neutral productuntil the sodium is substantially completely consumed, and subsequentlytreating the resulting alkaline product with fullers earth.

6. A process for refining a hydrocarbon oil comprising agitating saidoil in the liquid phase with an amount of. sodium less than thatrequired to produce a neutral oil and at a temperature of 109 to 250 C.until said sodium is substantially completely consumed, filtering thesolid reaction products from said 011 and agitating the resultingalkaline refined oil with sufficient fullers earth produce a neutralproduct.

'I. A process for refining hydrocarbon oil which comprises agitatingsaid oil in the liquid phase at a temperature of 100 to 250 C. with aquantity of sodium less than that which would produce a neutral oilsubstantially completely reacted alone with said oil, together with suchamount of fullers earth that a neutral product is obtained on completereaction of thesodlum and continuing the aforesaid operation until thesodium is substantially entirely consumed.

8. A process for refining hydrocarbon oil which comprises agitating saidoil in the liquid phase with a quantity of. molten alkali metal lessthan that required to produce a completely refined, neutral oil untilsaid metal is substantially completely consumed whereby an alkaline oilcontaining soluble reaction by-products is obtained, filtering saidalkaline oil to remove any insoluble materials present and finallytreating the filtered oil in the liquid phase with sufilcient adsorbentmaterial to precipitate said reaction by-products and produce a neutraloil.

9. A process for refining hydrocarbon oil which comprises agitating saidoil in the liquid phase with a quantity of molten sodium less than thatrequired to produce a completely refined, neutral oil until said sodiumis substantially completely consumed whereby an alkaline oil containingsoluble reaction by-products is obtained, filtering said alkaline oil-toremove any insoluble materials present and finally treating the filteredoil in the liquid phase with sufiiicient adsorbent material toprecipitate said reaction by-products and produce a neutral oil.

i 10. Aprocess for refining hydrocarbon oil which comprises agitatingsaid oil in the liquid phase with a quantity of molten sodium less thanthat required to produce a completely refined, neutral oil at atemperature of 100 to 250 C. until said sodium is substantiallycompletely consumed, whereby an alkaline oil containing solublereacremoving insoluble material from said oil, the

quantity of said adsorbent material being such that a neutral oil isobtained and the quantity of said alkali metal being such that itcompletely reacted alone with such oil, an alkaline oil would .beformed.

12. A process for refining hydrocarbon oil comprising agitating said oilin the liquid phase simultaneously with molten sodium and an adsorbentmaterial until said sodium is substantially comp'letely consumed andthereafter removing insoluble material from said oil, the quantity ofsaid adsorbent material being such that a neutral oil is obtained andthe quantity of said sodium being such that if completely reacted alonewith such oil an alkaline oil would be formed.

PAUL J. CARLISLE.

I CERTIFICATE OF CORRECTION.

E atent No. 2,058,131.

I PAUL J. YCARLISLE.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3,-second column, line 66, claim 6, strike out the word "refined"; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of December, A. D. 1936.

Henry Van Arsdale e Acting Commissioner of Patents.

October 20, 1936.

